渤海古近系辫状河三角洲储层描述配套技术——以锦州25-1南油田沙河街组为例

Supporting Technology of Reservoir Description for Braided River Delta with Bohai Paleogene——Taking Shahejie Formation of South Oilfield of Jinzhou 25-1 as Example

因沙河街组储层埋藏较深,沉积相类型较复杂,储层横向变化较快,且地震资料品质较差,沙河街组储层的描述难度很大。针对以上技术难点,建立辫状河三角洲储层描述的"四步法"技术体系,即背景岩性分析砂层组技术、目标层地质模式分析技术、模式约束地震相分析技术、恢复古地貌储层描述技术。以锦州25-1南油田为例用此方法预测沙二段储层的展布规律。从开发井结果看,锦州25-1南油田沙二段新井全部钻遇设计油层,且基本上为自喷生产,平均单井产油能力为225m3/d,产气量为3×104m3/d,油藏开发效果好。

It is difficult to characterize efficiently reservoir in Shahejie formation due to the deeply buried reservoirs, complex sedimentary facies, obvious lateral alternation of sand body and poor seismic quality. In view of the above technical difficulties, the ＂Four Steps＂ techniques system of reservoir description of braided river delta facies is founded： sand group analysis according to lithologic background, geologic model analysis of the target strata, seismic facies analysis constrained by the geologic models, and reservoir description with restoring paleogeomorphy. In this paper, the adjustment plan of south oilfield of Jinzhou 25-1 is take as an example to discuss the application effect of this system, and the result shows that all of the new wells aiming at Sha-2 member in south oilfield of Jinzhou 25-1 are drilled to the designed reservoirs, and mostly are flowing production and average production of single well is 225 m3 oil with 3 × 10^4 m3 gas per day, which suggests good reservoir development effect.